| Abbreviation | Definition |
|---|---|
| UJM | Unbelievable Jolly Machine |
| UK | Ugly Kids |
| UKK | University of King Kong |
| ULF | Ultra Large Female |
| ULM | Undarius Like Meanness |
| ULM | University Of Lower Mentality |
| UM | University Of Morons |
| UMA | United Military Assassins |
| UMA | Universal Multipurpose Agency |
| UMD | Unbelievable Magic Disc |
| UMF | Utterly Mad Freak |
| UML | Underappreciated Modeling Language |
| UML | University Of Manchester Language |
| UML | Useless Modeling Language |
| UMM | Undefined Mad Men |
| UMM | Unholy Men Of Mars |
| UMNO | Useless; Make Noise Only |
| UMS | Ultra Much Space |
| UN | Un Nutted |
| UN | Unanimously Neglectful |